Case Presentation

1
Case Presentation

• 52 year old man with a history of PNH originally
  diagnosed in 1978 (at age 28) when he presented
  with dark urine and was noted to have moderate
  hemolytic anemia
• Treated initially at that time with prednisone
  and blood transfusions. Had a relatively mild
  course with infrequent episodes of hematuria and
  very few blood transfusions
• Did not see a hematologist for over 20 years

2
Case Presentation

• Presented in April 2002 with abdominal pain and
  distension and was noted to be jaundiced
• Hepatitis workup was negative but an MRI of the
  abdomen revealed hepatic vein thrombosis
  (Budd-Chiari syndrome)
• Underwent a transjugular liver biopsy on 4/23/02
  which revealed extensive fibrosis, no cirrhosis,
  sinusoidal dilatation and central vein fibrosis
  consistent with Budd-Chiari syndrome
• Despite anticoagulation and numerous
  paracenteses, refractory ascites was present and
  he underwent a TIPS procedure in 7/02

3
Case Presentation

• Patient subsequently developed hepatic
  encephalopathy, requiring multiple hospital
  admissions over 2 months following TIPS placement
• Ultrasounds confirmed patency of shunt
• Referred to Dr Bessler in 9/02. Evaluation
  revealed a jaundiced, mildly encephalopathic man
  with normal abdomen
• CBC revealed Hgb 11.9 with MCV 97.2, plt cnt
  90,000, ANC 2,700, INR 1.7, creatinine 0.8, and
  bilirubin 6

4
Case Presentation

• Flow Cytometry
• erthrocytes 17 CD59 deficient
• granulocytes 99.8 CD59/CD24 deficient
• monocytes 82 CD59 deficient
• lymphocytes 24 CD59 deficient
• Anticoagulation increased, folic acid started,
  and referred for consideration of hematopoietic
  stem cell transplantation

5
Paroxysmal Nocturnal Hemoglobinuria

• PNH is an acquired disorder of hematopoiesis
  characterized by intravascular hemolysis and
  manifested by episodes of hemoglobinuria and
  life-threatening venous thromboses
• Caused by a somatic mutation in PIG-A gene of a
  hematopoietic stem cell
• Cells derived from the abnormal clone are
  deficient in all surface proteins normally
  attached to the cell membrane by a
  glycoslphoshpatidylinositol (GPI) anchor

6
Paroxysmal Nocturnal Hemoglobinuria

• First described as a clinical entity in 1882
• Cardinal diagnostic test, introduced in late
  1930s by Ham, is based on the increased
  sensitivity of PNH erythrocytes to lysis via
  complement
• Deficiency of a surface antigen acting as a
  complement defense protein (CD59), is largely
  responsible for the hemolysis and implicated in
  the thrombotic tendency

7
GPI Linked Proteins
Rosti, Haematologica, 2000
8
GPI anchored Proteins
Johnson and Hillmen,Mol Pathol, 2002
9
PNH Defect
Hillmen and Richards, Br J Haematol, 2000
10
Diagnostic Tests

• Acid hemolysis (Ham test) specific but not very
  sensitive
• Flow cytometry
• evaluate for presence/absence of GPI-linked
  proteins on hematopoietic cells
• CD55 and CD59

11
Flow Cytometric Analysis
Hillmen et al, NEJM, 1995
12
Clinical manifestations of PNH

• Highly variable and dependent upon the size of
  the abnormal clonal population in any individual
• Hemolysis
• mild to very brisk
• dependent upon
• size of abnormal clone (1-gt90)
• content of complement defense proteins
  (PNHII/III)
• presence of concomitant infection or other factor
  activating complement

13
Clinical manifestations of PNH

• Thrombosis
• Hepatic vein most common
• common cause of fatality
• Cerebral vein thrombosis
• sagittal sinus in particular
• Abdominal veins
• Dermal veins
• Pulmonary embolism unusual

14
Clinical manifestations of PNH

• Relative/absolute bone marrow failure
• present to some degree in all patients
• relative granulocytopenia/thrombocytopenia
• decreased capacity to form myeloid colonies
• Two stage model
• somatic mutation in PIG-A gene
• some cause for bone marrow failure
• Is damage directed at a GPI linked molecule?

15
Dual Pathogenesis Hypothesis
Hillmen and Richards, Br J Haematol, 2000
16
Natural History of PNH
Hillmen et al, NEJM, 1995

• Long term study of 80 patients with PNH seen at
  one institution between 1940 and 1970
• Results
• median age at diagnosis 42 (16-75)
• median survival 10 years
• 28 survived more than 25 years
• 39 had one or more episodes of venous thrombosis
• 12 experienced spontaneous clinical recovery
• leukemia did not develop in any of the patients

17
Sites of Thrombosis in PNH
Hillmen et al, NEJM, 1995
18
Natural History of PNH
Hillmen et al, NEJM, 1995
19
Natural History of PNH
Hillmen et al, NEJM, 1995
20
Treatment

• Supportive, prevent complement activation
• prednisone
• Therapy for/prevention of thrombosis
• thrombolytics acutely
• anticoagulation
• Stimulate hematopoiesis
• G-CSF
• Immunosuppression
• ATG
• Cyclosporine

21
Treatment

• Stem Cell Transplantation
• syngeneic
• autologous
• Allogeneic
• related
• unrelated
• Ablative
• Non-myeloablative
• Gene Therapy?

22
Circulating Stem Cells in PNH
Johnson et al, Blood, 1998
23
Stem Cell Transplantation in PNH

• Summary of single institution trials
• Approximately 12 reported
• Number of patients ranges from 1-16
• Survival rates typically higher (58-100)
• Likely high degree of reporting bias, based on
  outcomes seen using registry data

24
Stem Cell Transplantation in PNH
IBMTR Data Saso et al, Br J Haematol, 1999
25
Results

• Sustained engraftment 77
• Graft failure 17
• Grade 2-4 acute GVHD 34
• Chronic GVHD 33
• Causes of death
• graft failure (7), int. pneumonitis (4), GVHD
  (3), infection (3), ARDS (2), hemorrhage (1)

IBMTR Data Saso et al, Br J Haematol, 1999
26
Stem Cell Transplantation in PNH
Matched siblings
IBMTR Data Saso et al, Br J Haematol, 1999
27
Stem Cell Transplantation in PNH
Matched siblings
IBMTR Data Saso et al, Br J Haematol, 1999
28
Stem Cell Transplantation in PNH

• EBMT Database (unpublished)
• 46 transplants using HLA-ID sibs reported from
  1979 to 1997
• Median age at diagnosis 29 (10-46)
• Median interval from diagnosis to BMT 794 days
  (30-8680)
• Actuarial 5 yr survival 52
• Main cause of death acute GVHD

29
Stem Cell Transplantation in PNH
Patient Characteristics
Transplant Outcomes
Raiola et al, Haematologica, 2001
30
Stem Cell Transplantation in PNH
Raiola et al, Haematologica, 2001
31
Stem Cell Transplantation in PNH
Flotho et al, Br J Haematol, 2002
32
Stem Cell Transplantation in PNH

• Conclusions from reported series
• BMT may cure 50-60 of selected patients with
  HLA-identical siblings
• Most patients transplanted have been lt 30 years
  of age
• Regimen related toxicity and GVHD remain
  significant hurdles
• Role of alternative donor transplants unclear,
  though initial reports are not encouraging except
  in pediatric population

33
Stem Cell Transplantation in PNH

• Open questions
• What degree of conditioning is necessary to fully
  eradicate PNH clone?
• Is immunosuppression sufficient?
• What is the role of non-myeloablative
  conditioning?
• What is the role of T-cell depletion?
• What if patient has advanced PNH but lacks an
  HLA-identical sibling donor?

34
Non-myeloablative Transplantation in PNH

• Rationale
• Decrease toxicity and potentially lower risk of
  GVHD associated with standard regimens
• Provide immunosuppression sufficient for
  engraftment of donor hematopoietic cells and
  potentially for eradication of PNH clone via
  cytotoxic T-cells
• Allow transplantation in patients with more
  advanced PNH
• Case report from Japan demonstrated feasibility
• Suenaga et al, Exp Hematol, 2001

35
Low Intensity Conditioning

• Low dose TBI/CSA/MMF
• Flu/Cy
• Flu/Bu/ATG
• Cy/Low dose TBI
• Flu/Melphalan

36
Non-Ablative Stem Cell Transplantation
Barrett and Childs, Br J Haematol, 2000
37
Non-myeloablative Transplantation in PNH
Takahashi et al, ASH, 2002

• Transplanted 5 patients with hemolytic PNH and
  RBC transfusion dependence
• Less toxic fludarabine (125mg/m2) and
  cyclophosphamide (120mg/kg) conditioning regimen
  used
• GPI-negative neutrophils eradicated in all 5 by
  day 115
• Demonstrated generation of miHa specific CTL
  capable of lysing both GPI-negative and positive
  B-cells no eveidence of decreased sensitivity to
  T-cell mediated lysis in PNH cells could be
  identified
• All 5 survive without PNH from 5-39 months post
  transplant

38
Prognosis Based on Management
Luzzatto, Haematologica, 2001
39
PNH Management Guidelines
Luzzato, ASH, 2001